src: remove duplicate loop

Two identical `while` loops after each other can be folded into
a single one.

PR-URL: https://github.com/nodejs/node/pull/14750
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Khaidi Chu <i@2333.moe>

src/env.cc

@@ -105,9 +105,6 @@ void Environment::CleanupHandles() {
 
   while (handle_cleanup_waiting_ != 0)
     uv_run(event_loop(), UV_RUN_ONCE);
-
-  while (handle_cleanup_waiting_ != 0)
-    uv_run(event_loop(), UV_RUN_ONCE);
 }
 
 void Environment::StartProfilerIdleNotifier() {